The present invention relates to apparatus for providing a skin incision in order to cause bleeding and more particularly to a disposable device which provides a precisely controlled incision in the skin of the patient.
Devices for producing skin incisions in the skin of a patient are known in the art and essentially are utilized to permit observation of the bleeding time. The bleeding time is defined as the time between implementing the incision and the moment when the bleeding stops. This is a well known test to determine the ability of blood platelets to stop bleeding from injured vessels. Many techniques have been described in the literature as well as in certain prior art devices. Essentially, bleeding tests were first performed by surgeons or technicians who employed a scalpel to make an incision which was a relatively small incision at a relatively small depth. Such wounds as implemented by scalpels or lancets produced incisions which were 5 to 10 mm long and 1 to 5 or more mm deep. The need for disposable devices to automatically produce such incisions was apparent due to the fact that many persons have fear of a scalpel as well as the further fact that the length and depth of the incision was a pure function of the ability of the practitioner and hence such incisions could vary widely depending upon the skills of the practitioner.
To circumvent such problems, a series of devices are described which essentially seek to provide a standardized skin incision in order to cause bleeding so as to make it proper to determine bleeding time as above indicated. U.S. Pat. No. 3,902,475 which issued on Sept. 2, 1975 entitled DEVICE FOR MAKING SKIN INCISIONS by Geoffrey Berg et al shows a device for forming a skin incision which device has a base plate having a lower surface which is adapted to be placed against the skin of a patient. The base plate has an elongated aperture. Extending from the base plate is a support member having a cutting edge which is aligned with the aperture. The device includes a fixed pivot for mounting said support member and cutting edge for pivotal rotation about an axis parallel to the slot.
Upon actuation of the instrument, the cutting edge moves through an arc of a circle from points above the lower surface of the base plate and then enters the slot where the cutting edge projects into the patient's skin during the arcuate path and makes an incision over a given length. This device, while eliminating the above noted problems of manual incisions, has many disadvantages. First the device produces an incision which is not of a uniform depth based on the fact that the cutting edge traverses an arc. Hence the incision made is longer than necessary in order to obtain at least a length of 5 mm at a depth of at least one or more mms to assure bleeding. Due to the pendulum-like path, the incision is arcuate and is not of a constant depth. Hence most of the cut made by this instrument does not produce bleeding. Although the instrument is simple in structure it has the above noted disadvantages.
U.S. Pat. No. 4,078,552 entitled DEVICE FOR AND METHOD OF MAKING STANDARD AND REPRODUCEABLE SKIN PUNCTURES issued on Mar. 14, 1978 to Evan N. Chen et al and assigned to the Warner-Lambert Company. This device is commercially sold under the trade name SIMPLATE. Essentially, as is disclosed in the patent, the device contains a blade or cutting edge which is located in a housing and which housing contains a blade aperture. The blade is supported by a post which post has a spring surrounding the same. When a release mechanism associated with the housing is activated, the spring pushes the blade downwardly much like the action of a guillotine, and hence the blade penetrates the patient's skin in a downward thrust as in the vertical direction making a standard puncture which puncture is approximately 5 mm in lenth and 1 mm in depth. This device, while having gained wide spread acceptance has many problems associated therewith.
First, the blade once activated to penetrate the patient's skin cannot be retracted and is exposed and is dangerous to both the technician and the patient. A further problem with the instrument is that the blade has to remain within the patient's skin for at least one second after it has been activated. This is due to the fact that a puncture which is made by a vertical thrust is not analogous to the type of incision made by a scalpel or to the incision made by the above noted device. Essentially, it is not a cut formed by moving a scalpel or blade along the skin but is a wound which is made by a downward thrust of a blade into the skin.
Both of the above noted patents contain various details concerning the need for bleeding time tests and include various explanations which are pertinent to the general problems.
It is, therefore, a major object of the present invention to produce apparatus for implementing a standardized skin incision which apparatus is disposable and which circumvents the above noted problems inherent in prior art devices.
The apparatus to be described produces a surgical cut which simulates the cut of a surgeons scalpel as opposed to an arcuate cut or puncture and produces the cut at the proper length and depth to assure accurate bleeding time measurements as required. A further advantage of the apparatus is that it is extremely simple to implement and manufacture. A further advantage of the apparatus to be described is that based on its operation, the cutting blade spends very little time in implementing the incision since the action is extremely rapid as compared to the apparatus for example shown in U.S. Pat. No. 4,078,552.